Rotary die creasing mechanism for corrugated paperboard



ink 12, 194% N. A. ANDERSON 2,475,868

ROTARY DIE CREASING MECHANISM FOR CORRUGATED PAPERBOARD Filed April 13, 1945 5 heets-Sheet 1 IN VENTOR.

NELs A. ANDERSON,

BYM27%WI ATTORNEY.

July 12, 1949. N A, ANDERSON 2,475,868

ROTARY DIE CREASING MECHANISM FOR CORRUGATED PAPERBOARD Filed April 13, 1945 5 Sheets-Sheet 2 NIQ l f JINVENTOR.

A T TORNEY 5 Sheds-Sheet 3 Filed April 13, 1945 July 12, 1949. ANDERSON 2,4758

R0 DIE CREASING MECHANISM F ORRUGATED PAPERBOARD ATTORNEY.

I July 12, 1949.

. R CORRUGATED Filed April 13, 1945 N. A. ANDERSON R0 Y DIE CREAS MECHANISM ERBOARD 5 Sheets-Sheet 4 EISE INVENTOR. /VL$. A. ANDERSON ATTORNEY.

y 1949. N. A. ANDERSON 2,475,868

ROTARY DIE CREASING MECHANISM v FOR CORRUGATED PAPERBOARD Filed April 13, 1945 5 Sheets-Sheet 5 EI ll INVENTOR.

NELS A. ANDERSON ATTORNEY which would be placed on the material by relative movement between the centers of the roller dies which would result from flexing or vibrating shafting. Also, for best results, the dies should have a predetermined dimensional relationship with respect to each other, and with reference to the thickness of the material, as will be pointed out more fully hereinafter.

Reference is now made to the drawings for a more detailed description of the invention, in which:

Fig. 1 is a more or less schematic, fragmentary, longitudinal sectional view of a form of machine embodying roller die mechanism of my invention, taken in a plane indicated by line I--l in Fig.

2 the dies being shown out of proportion to illustrate them more clearly.

Fig. 2 is a fragmentary front elevation of the machine shown in Fig. 1.

Fig. 3 is a more or less schematic, fragmentary front elevation, illustrating additional bearing supports for the roller die shafting, which may be employed if such shafting is not of sufliciently large diameter to have substantially no vibration or flexing.

Fig. 4 is a transverse sectional view of the mechanism of my invention, taken in planes indicated by line 4-4 in Fig. 1.

Fig. 5 is an enlarged, schematic fragmentary view illustrating a roller contact length and roller diameter relationship for corrugated paperboard which has only one layer of corrugated paper. The view is approximately double scale.

Fig. 6 is an enlarged, schematic fragmentary view illustrating a roller contact length and roller diameter relationship for corrugated paperboard which has two layers of corrugated paper, often designated in the trade as double double board. This view is approximately one and two-thirds (1%) scale.

Fig. 7 is an enlarged, schematic fragmentary view, approximately double scale, illustrating preferred die dimensions for corrugated paperboard which has only one layer of corrugated paper.

Fig. 8 is an enlarged, schematic fragmentary view, approximately double scale, illustrating preferred die dimensions for the so-called double double" corrugated paperboard.

Fig. 9 is an enlarged fragmentary sectional view of one form of corrugated paperboard before folding thereof, illustrating the type of crease formed by the roller die mechanism of my invention.

Fig. 10 is an enlarged fragmentary sectional view of the board of Fig. 9 folded to provide a right angle corner in a.container or the like.

Fig. 11 is an enlarged fragmentary sectional view of folded double double paperboard having a crease formed by the roller die mechanism of my invention.

Fig. 12 is a schematic plan view, on a reduced scale, of a creased and slotted blank of paperboard adapted for folding into box or container form; the crease lines in this view being illustrated merely by dotted lines for clarity.

Fig. 13 is a fragmentary top elevation looking in the direction of arrow 13 of Fig. 9.

Fig. 14 is a fragmentary bottom elevation looking in the direction of arrow ll of Fig. 9.

The roller die mechanism of my invention may be employed in place of roller knife scoring mechanism in well known forms of machines now employed by the industry for scoring or creasing corrugated paperboard. These machines usually contain mechanism for slotting the paperboard, and also printing mechanism, and are known to the trade as printer-slotters. Such machine usually comprises a framework 2 supporting conventional printing mechanism 3 which includes suitable power driven inking rollers 4. Conventional power driven slotting mechanism 6 is generally provided, which cuts out material from the blank 1 (Fig. 12) fed to the machine, to form slots 8 which, when the blank is folded along crease or hinge lines 9, form the top and bottom cover flaps l I of the resulting container. Crease lines 9 preferably run transversely at right angles to the corrugations; and running substantially parallel to such corrugations are crease or hinge lines l2 which, when the blank is folded, provide the sides I3 of the resulting container.

Hinge lines [2 are formed by the roller die mechanism l4 which follows the slotting mechanism 6 in the type of machine illustrated; although the slotting mechanism may follow the roller die mechanism, which is the order in other types of machines. Hinge lines 9, being transverse to the direction of feed of the material in the machine illustrated, may be formed either beforehand or subsequently by another machine.

Roller die mechanism l4 comprises a pair of rotatable shafts l6 journalled in suitable bearings H and which are driven by any suitable driving mechanism [3, only a portion of which is shown. as such driving mechanism is conventional. Pref erably, the bearings for one of the shafts are embodied in suitable adjustable eccentric mechanism [9, such as shown in United States Patents Nos. 2,030,027 and 2,030,028, both dated February 4, 1936, to provide for adjustment of the distance between the male and female dies on such shafts when this is desired. As was previously related, it is desirable. that shafts l6, have substantially no vibration or flexing when they are driven, to avoid possible tearing of the material, which might otherwise occur if the roller dies had substantial relative movement with respect to each other when they are driven. To obtain this result, the shafts are made of sufiiciently large diameter if they are provided with bearing support only at their ends. I have found that, for this purpose, the shafts, which are of the usual metal. should not be much less than six (6) inches in diameter in machines adapted to form a plurality of parallel hinge lines l2. The same result may be obtained with shafts of lesser diameter if they are provided with sufficient bearing supports 25 intermediate their length, as is shown in the modification of Fig. 3.

Each male roller die structure preferably comprises a die ring 21 having a continuous peripheral flange 28 which provides a male die member of a predetermined size to be described hereinafter. Preferably such die ring is split, and the parts thereof are fixedly but detachably secured to a split collar 29, by cap screws 3 l; the collar having a shoulder portion 32 on which the ring is seated, and the parts of the collar being fixedly clamped together about a shaft [6, by cap screw 33. Collar 29 may be additionally held against relative angular movement with respect to its mounting shaft, by key means 34 which permits axial adjustment of the die structure for forming the roller die crease at the desired location. In this connection, the detachable mounting of die ring 2'! enables ready employment of any desired size die member 28, as one die ring may be easily interchanged or substituted for another by virtue of the described arrangement.

The construction of each female die structure is, preferably, the same as that of the associated emazeas It" 1s-- mportan dfd'el to"-'avoid rupturing or "ei earrugatd paperboata that the fietfiall y the 'malamllr die; he of S fiiei'efitlyl' ge'diameter ta pYOV'i'd'e aibHef'66ntactlngth ori tfieqiaipen 'hoai d ofiat least me (5) 'times ithe '0ver=al1 "thickness the Ward; -s\ich ever aHthickness beihg the total width betw een "the outer surfa'; s of 'th'e 'beard'. Ih'-c0mmercia1 cdrmgalted -pap b'OaTd cc i'ntaihing Che =1ayer 6f em nugated pape'r 41 (Figs. 9 and 10) "aidhesively "uifited' between euter layers 42: of plafie paper, "the ovet allthickness T '(Fig. will. usually wary from four thirtfishcohdths /32) to: fi-Ve thint'y-secondths 2) otaninch, depending oh tlie-vthtekne'ssdftheindividual: l'ayers'bfithe paper- If:ear'd afid the height of the-corrugations;

Increasing:suehibdatd, the extent of pmj action of male die m8mbr*2-fl-Fig. 7 firdmipetipheial :surfaee fl 'on the male "i oifler, anti the" d'epth of female-die slo't 31i are 'sueh,' th'at the" distance'between.- malepetiphe'rali surface 38' "andf-'the reot face-M oft-he female die, will' 'efiect pressure-on the beardvsufflcient toicause" tho'rmigh down-pasting or compressing: the material: in slot 4 31' but insufficient tezcaus'erruptnring: thereof. *Fbrhuatdi con- 'taihing one layer of -curtu-galtedx earner;ssuch distance will' :generally i be approximately fine-third 6 *6f-=-thebve1-a11thickness 0f-=the board, with slight variations depending on the thickness* of the individ'lialr layers 0f "the :paper iormi'n'g'the beard and the height?of= the-corrugatioria Ins-this' connection; the spacing-between roller surfaces 39 and 43 on 'the-center'dinefi is-s'iich that there will: be-substantially no drivinghontact on the material -by suehsurfaces: as the rollers are-driven; Thus, this ditane'e iSJ'preferably made slightly greater than the over-all thickness of theboa'td; 'lhetpreviouslydescribed adjustable mountingbfi the roller .dies relative to each other i permits i one' t'o set up-theamachine readily fer obt'airiingthe desired-J spadedf-rel'ation- "shiprbetw e'en the'dies.

To 'ohta'in'th'e d'esired 'roll'er' contact-length, I -have found "that the female 'rolle'r diameter 8 hea-fihg 'sfir 'face for the material. 'I-'-his" "diameter, dwever, is not partieul'aitly riti cal; Pheuse it 'is the' 'male die'roller which primarily Q the creasing, and causes penetra'tidn of th material ititothe female 'die 31. "Admineter "bf at least about six (6') inches-wilt be sufficient for the female roller. In creasing-board having only a single layer of" corrugated paper and anbver allthickness of 1 abdut between four lo tl ii'nty-e'eedhdths 6 /32) and'five thirty secondths %-2 fan inchjthe' male roller shouldn'otF-Be iitueh -'1'ess than "seven 4 ('7) indhes in diameter, "altho'figh the gi'eate'r'this diameteris, the-het- "tei'j-heeauee the i'o'ller contact length "will" inwei'ease "with increase in diametefbftheifla-Ie roller.

"Fig; 5 -il1u'strates 'a roller diameter ielatibnsh-ip i01 corrizgated paperboard having only onelayer bf cetrugatd 'paiiier "and which has" an: oVena'll go-th-ichriees of"four thiity' secondths ofln inch; "The female die roller-is si-x (6)inchestn diameter; the" diameter beirigs measured "to the ciuterFpeTipheTaI"surface 39; and the'male die roller *diameteris eight ('8) inches, the diameter :2 being "measured to the peripheral surface "6f "'male 'die' member 28. -The 'depthbf'female *recess 3 1 is i preferably five "sixty-fotirths- /w), of an inch, which is: satisfactory for all commercial thicknessesbflhoai d.

a direction indiated' by the "direction arrows, ahd thepertienof one s'ui'fa'ce-of thefiaperheaid '35 not being creased, namely the 'iaortibn outside' 7 having only one layer of corrugated. paper. With board of this type, the male roller die should for best results be at least fourteen (14) inches in diameter, while the female roller die, although it may be as small as six (6) inches in diameter,

should for best results be at least seven (7) inches in diameter.

Figs. 6 and 3 illustrate a roller die relationship for double double paperboard P having an over-all thickness of ten thirty-secondths %2) of an inch; the male die roller diameter being fourteen (14) inches, and the female die roller diameter being seven ('7) inches. Because of the increased over-all thickness of board, the periphery 38 of male die member 28 should be spaced a slight distance from the female roller periphery 39, at center line C; the spacing being such as to cause thorough compacting of the material in the slot 31 without rupture thereof. Usually, such spacing will be approximately onefourth A) the over-all thickness of the board. In this conection, the depth of female recess 31 is preferably five sixty-fourths (%4) of an inch, which, as was previously mentioned, is satisfactory for all commercial thicknesses of board. Thus, at center line C, the distance between male peripheral surface 38 and root face M of the female die, will be approximately one-half the over-all thickness of the board.

The spacing, at center line C, between peripheral surfaces 39 and 33 of the dies should be approximately equal to the over-all thickness of the board but, preferably, slightly reater, so that these surfaces do not have substantial driving effect on the board. The rollercreasing contact length, indicated by distance D, is about one and thirteen-sixteenths (1+2) of an inch. In this connection, the male die roller may be larger if so desired because the greater the diameter thereof, the less rupturing effect there will be on the board as it is being creased.

When the machine embodies a plurality of laterally spaced cooperating pairs of the roller dies positioned side by side, as is usually the case,

a lateral pull or stretching is imposed on the material as the male dies indent it into the female dies. To lessen this pull, and thereby minimize rupture which might otherwise result, it is desirable to have some of the male die members 28 of slightly less diameter. For this purpose, I preferably make every other male die member 28 about fifteen to twenty thousandths (0.015 to 0.020) of an inch less than the diameters of the other male dies. The same result may also be obtained, for example, by making the inside male dies of slightly less diameter than the outside male dies, or vice verse.

For best results, the width of the male and the female dies should have a predetermined relationship with respect to the over-all thickness of the corrugated paperboard. If the dies are too narrow in width, then when the board is folded along the resultant die crease, tearing and an unsightly hinge line may result. If they are too wide, the

hinge will develop too much play when the boardis folded, which is undesirable because the ri idity of the resulting container will be impaired, causing loss in strength. Preferably, the male die member 28 should have a width approximately equal to the over-all thickness of the board, and the female die recess 3'! should have a width approximately twice the width of the male die, or in other words, approximately twice the overall thickness of the board. Also, the male die member 28 should be centered with respect to the female recess 31; so that substantially the same spacing obtains between each side of male die member 28 and the adjacent side of female recess 31.

Fig. 7 illustrates the preferred die dimensions for corrugated paperboard having a single layer of corrugated paper and an over-all thickness of five thirty-secondths (3%) Of an inch; male die member 28 being five thirty-secondths (5 of an inch wide, and female recess 37 being twice such width. In Fig. 8, the preferred dimensions are illustrated for double double board having an over-all thickness of ten thirty-secondths of an inch; the male die member 28 having this width and the female recess 31 twice such width. This described die width relationship is preferred for best results, but may vary plus or minus one sixty-fourth 4 4) of an inch either way; so that the male die member width will still be substantially equal to the over-all thickness of the paperboard, and the female die recess width substantially twice the over-all thickness of the paperboard.

As can be seen from Figs. 9, 10, 13 and 14, the die crease results in positive indentation 5| of the material, forming depressed inner and outer surfaces of substantial width which results in a straight hinge edge for folding. The surface 52, which forms the inner surface of the container when the board is folded at a right angle, and which is acted upon directly by male die member 28, has two definite inner and parallel crease lines 53 below the plane of surface 52 and which are formed by the spaced edges or corners of male die member 28. These crease lines are spaced apart substantially the width of such male die member 28, which is substantially the over-all thickness of the material. Crease lines 53 are between outer parallel crease lines 55 which are formed by the pressure acting against the edges or corners of the female die recess 31; the crease lines 53 and 54 being joined by flat surfaces 56 which have relative outward slant with reference to the depressed portion of surface 52. Because of the pull on surface 52 effected by the dies, the distance between crease lines 54 will be somewhat less than twice the over-all thickness of the material, depending on the pressure.

Surface 51 of the board, which forms the outer surface of the container when the board is folded at a right angle, and which is acted upon directly by the female die part 31, has two definite parallel crease lines 58 which are spaced apart a distance substantially twice the over-all thickness of the paperboard because they are formed by the edges or the corners of the female die part 31. As a result of the described creasing, the walls adjacent the crease may be folded at a right angle with respect to each other to form a rigid and true or straight corner, as is illustrated in Fig. 10. Also, such walls may be folded against each other, for shipping or storage purposes, without tearing of the hinge or crease line.

The same crease line arrangement and proportional relationship will be formed on the double double board which is shown with a right angle fold in Fig. 11; and the same reference characters are, therefore. applied in this view.

Because of the positive parallel crease lines and the positive indentation of the board that are formed by the dies of my invention, a hinge connection obtains which permits folding of the container blank into container form without any bulging of the sides, making for a nice appearing as well as strong container. In this connection,

the described male and female die relationship with respect to each other, and with respect to the over-all thickness of the board may be utilized in so-called bar creasing mechanism, comprising elongated relatively reciprocating male and female dies, and produce my desired type of crease or hinge in corrugated paperboard.

I claim:

1. Roller die creasing mechanism for corrugated paperboard comprising a male roller die and a female roller die, the male roller die including a male die member having a width substantially equal to the over-all thickness of the paperboard, and the female roller die having a die recess the width of which is substantially twice the width of the male die member.

2. Roller die creasing mechanism for corrugated paperboard comprising a male roller die and a female roller die, the male roller die including a male die member having a Width substantially equal to the over-all thickness of the paperboard, and the female roller die having a die recess the width of which is substantially twice the width of the male die member, the diameter of the male roller die member being such as to provide a roller contact length on the board of at least five times the over-all thickness of the board.

3. Roller die creasing mechanism for corrugated paperboard comprising a male roller die and a female roller die, the male roller die including a male die member having a width substantially equal to the over-all thickness of the paperboard, and the female roller die having a die recess the width of which is substantially twice the Width of the male die member, the diameter of the male roller die membr being such as to provide a roller contact length on the board of at least five (5) times the over-all thickness of the board, and meansv mounting such roller dies against substantial vibratory movement relative to each other when they are driven.

4. Roller die creasing mechanism for corrugated paperboard comprising a plurality of pairs of cooperating male and female roller dies positioned side by side to form a plurality of parallel creases in the board, some of the male roller dies being slightly less diameter than the other male dies to minimize pull on the material as it is being creased.

5. Roller die creasing mechanism for corrugated paperboard comprising a plurality of pairs of cooperating male and female roller dies positioned side by side to form a plurality of parallel creases in the board, some of the male roller dies being of slightly less diameter than the other male dies to minimize pull on the material as it is being creased, and the diameter of each male roller die being such as to provide a roller contact length on the board of at least five (5) times the over-all thickness of the board.

6. In die creasing mechanism for corrugated paperboard, a male die member and a cooperating female die member, the male die member having a width substantially equal to the overall thickness of the board, and the female die member having a die recess the width of which is substantially twice the width of the male die member.

'7. In roller die creasing mechanism for corrugated paperboard, opposed rollers between which the board is passed, a female die groove formed in one roller, and a cooperating male die tongue formed on the other roller, the depth of said tongue exceeding the depth of said groove sufficiently to compress the board between the die parts without establishing driving contact between the board and the peripheral surfaces of the rollers, said male die tongue having a width substantially equal to the thickness of the paperboard, and the female die groove being substantially twice the width of the male die tongue.

NELS A. ANDERSON.

REFERENCES CITED The following referenlces are of record in the file of this patent:

UNITED STATES PATENTS 

